10 Best 4-Channel Car Amplifiers in 2024 – Reviews & Top Picks

To get the best audio experience possible in your car, you’ll need to bring together a few key components that depend on each other for optimal music reproduction. One of these components is a separate amplifier, which will help your speakers produce the best sound they can. A four-channel amp will give you the most flexibility, power, and seat-shaking bass potential.

One significant advantage of a four-channel amplifier is the option for bridging channels. You can connect two speakers to each channel, which will give you the option of having up to eight speakers. Alternatively, two channels bridged together will give you more power for sub-woofers.

Finding the right amp to fulfill your dreams of window-shattering bass can be confusing. Terms like “high-pass crossover” and “ohms” can make you just want to stick with your standard car stereo. You can ignore the flashy terms and technical jargon; we have you covered! We’ve compiled a list of the best four-channel amplifiers available to help you make the right decision for your needs.

A Quick Comparison of Our Favorites:

Rating	Image	Product	Details
Best Overall		Alpine 4-Channel Car Amplifier	Compact size Quality sound for a class D amp Efficient and will not overheat	CHECK PRICE
Best Value		BOSS Audio R1004 4 Channel Car Amplifier	High power output Full range High-quality audio output	CHECK PRICE
Premium Choice		Skar Audio RP 4 Channel Amplifier	High power output Four-way circuitry protection MOSFET power supply	CHECK PRICE
		Kenwood KAC-M3004 4 Channel Digital Amplifier	Inexpensive Compact	CHECK PRICE
		Planet Audio AC800.4 4 Channel Car Amplifier	A/B class for superior volume and clarity Variable gain control and bass boost MOSFET power supply	CHECK PRICE

The 10 Best 4-Channel Car Amplifiers:

1. Alpine MRV-F300 4-Channel Car Amplifier — Best Overall

The Alpine MRV four-channel amplifier tops our chart and is our best overall pick due to its compact size, beautiful brushed metallic finish, and sound quality that Alpine is so well known for. Not only is it a reliable and popular brand, but its price won’t empty your pockets. This amp will give you four 75-watt RMS channels at 2 ohms and four 50-watt RMS channels. This impressive power is packed into such a small, lightweight package.

For a class D amplifier, it runs with far less noise than you’d expect, and the audio quality is far superior to other amps in a similar price bracket. Class D amps provide compact power efficiency, and the Alpine is one step ahead of the competition.

2. BOSS Audio R1004 4 Channel Car Amplifier – Best Value

When you want the best 4-channel car amp for the money, the Boss R1004 delivers. Boasting four thumping 100-watt channels at 2 ohms or 50 watts at 4 ohms, this amp packs a punch. It’s a full-range amp that can run your speakers and sub-woofers.

As a class A/B amp, it has plenty of current flowing through it, which equals massive power. However, it’s also incredibly bulky and measures 7.8 x 9 inches, which keeps it from our top spot.

This is a non-issue to power-hungry audiophiles, but for a smaller car, it can become a real problem; ideally, you’ll want it out of sight underneath your seat. This massive power and well-known Boss quality will not disappoint, even for the slightly higher price.

3. Skar Audio RP 4 Channel Amplifier – Premium Choice

The Skar RP is a 1,000-watt, A/B class powerhouse. It has an RMS rating of 250 watts at 2 ohms per channel and 125 watts at 4 ohms. It’s an amp for people who want power behind their speakers.

The Skar has a practical four-way protection circuitry design, which will protect your speakers from blowing out if they overheat. It also has a high-quality MOSFET power supply, known for its superior quality. It is rather bulky, coming in at 7 x 24 inches, but you’d expect this for a class A/B amp. Its large size and high price keep it just below our two top spots.

4. Kenwood KAC-M3004 4-Channel Digital Amplifier

The Kenwood KAC is a class D amplifier that’s affordable and compact. It has an RMS range of four channels at 75 watts at 2 ohms and 50 watts at 4 ohms. It’s rated at 300 watts total, which is more than sufficient for most users. However, this won’t give you the volume possible with higher-power amps. Since it’s a class D amp, cranking the volume up too high will result in a high signal-to-noise ratio.

This means that you’ll get more signal noise compared to a class A/B amplifier. However, the Kenwood is an affordable option that will give you a far better sound than a standard stereo, albeit without the clarity or decibel-meter-topping volume that a higher power amp is capable of.

5. Planet Audio AC800.4 4-Channel Car Amplifier

The Planet Audio AC800 sits comfortably in the middle of our list, even though it’s a class A/B, full-range, 800-watt amplifier. It has a variable gain control and bass boost and comes in with a power rating of 200 watts at 4 ohms and 100 watts at 2 ohms RMS. On top of that, it has a high-quality MOSFET power supply.

What drops it to number five is its notoriety for unreliability. It’s known to cut out regularly, likely due to its built-in protection mode. This is a useful addition to prevent overheating, but users complain that it happens far more often than it should.

6. BOSS Audio Systems AR1600.4 4-Channel Car Amplifier

The Boss AR1600 is a class A/B 1600-watt amplifier boasting four channels of 400 watts at 2 ohms or 200 watts at 4 ohms. That is a ton of power for an amp this affordable. It also features a variable bass boost and a high-pass crossover for improved frequency reproduction.

Users report that the thermal protection overload cuts out audio far sooner than it should. This is a frustrating issue for a brand of this caliber. Users also reported that it doesn’t have the punch you would expect from the impressive specifications.

7. JBL GX 435W 4-Channel GX Series Amplifier

JBL is a well-known brand in the audio world for its quality products. The GX car amplifier has a sleek design,  and its RMS rating comes in at 60 watts per channel at 4 ohms or 85 watts per channel at 2 ohms. It also has a variable bass boost and low-pass filter.

What it lacks in power, it makes up for in quality. JBL makes top-notch audio products with crystal-clear sound. This amp is perfect for smaller but accurate sounds, but you may be left wanting should you need to connect a sub-woofer or are hoping for deep bass frequencies.

8. Rockville dB45 4-Channel Car Amplifier

This Rockville dB45 is not lacking in power. It’s an earth-shaking A/B class amplifier pumping out 3,200 watts. Its RMS rating is 270 watts per channel at 4 ohms and a staggering 400 watts per channel at 2 ohms. It also boasts a MOSFET power supply, an adjustable 12 dB crossover, and an adjustable bass equalizer.

With all this power come a few caveats. The amp can be difficult to set up, with low-quality screws that strip easily. It’s also known to overheat quickly, with some users claiming that it gets too hot to touch. This will cause it to cut out regularly.

9. Blaupunkt AMP1504 Full-Range Amplifier

Blaupunkt is known for its quality yet affordable audio products. This full-range, class A/B amp has a peak power rating of 1,500 watts, with an RMS rating of 300 watts at 2 ohms per channel and 150 watts at 4 ohms per channel.

While these specifications seem fine on the outside, several issues have been reported. This amp overheats frequently. The brand is also known for its unreliability and lousy customer service. However, some users have had no issues, and the Blaupunkt is an affordable and powerful amp if you’re willing to take the chance.

10. AUDIOPIPE 120 Watt 4 Channel Car Amplifier

This class A/B Audiopipe amplifier has an output of 120 watts RMS per channel at 4 ohms and 170 watts per channel at 2 ohms. Since Audiopipe isn’t a well-trusted name in the audio world, buying this amp could be a gamble. However, its affordable price, decent power output, and MOSFET power supply may make it a worthwhile risk.

It has a reputation for overheating quickly, despite its claim that the aluminum casing helps to keep it cool. This, of course, will cause the amplifier to shut off. Since Audiopipe is a smaller player in the market, the parts and warranty can quickly become an issue.

Buyers Guide – Purchasing The Best 4-Channel Amp

A four-channel amplifier is similar to its two- and five-channel counterparts in that it uses a single power supply to increase the 12V output and supply higher power. Standard car stereos usually rely on the 12V current directly from the car’s battery, which doesn’t provide enough power for sub-woofers. A four-channel amplifier allows you to add up to four separate speakers and bridge the channels for even more power.

However, there are several factors to consider when buying a four-channel amplifier.

Crossovers

Ideally, you want your amplifier to have high-pass and low-pass crossovers. It’s even better if they are adjustable but not essential. A high-pass crossover allows frequencies above the cut-off frequencies to pass through to your speakers.

A low-pass crossover allows frequencies below the chosen cut-off. This blocks frequencies from getting to speakers that cannot handle them, preventing distortion and blown speakers. It also gives you far cleaner audio quality.

A/B Class and D class

Another important consideration is the amplifier class. The main difference comes down to efficiency. Class A/B amps are the least efficient but offer the best sound fidelity. Class D amps will give you far more efficiency but less audio quality.

The amplifier class is defined by how the amp combines the power and signal. Every amp will consume more power than it can feasibly put out. An amp’s efficiency rating is the ratio of what it can put out divided by its power consumption.

No amplifier can be 100% efficient. It can never put out more power than it draws. The power that’s drawn and not used for the output of audio creates heat. Too much heat equals a burned-out amplifier.

A/B class amplifiers

These amplifiers are usually around 60% percent efficient, and the transistors inside are on only around half the time, even when no audio signal is present. Until recently, these amps have always been the go-to due to their superior audio quality, lack of noise and distortion, and full-range application. Class D amps have yet to come close regarding accurate sound production.

Class D

However, class D amplifiers are catching up quickly to the audio quality produced by A/B class amplifiers. They benefit from fitting into a much smaller chassis, making them far more compact and allowing them to be stowed away conveniently under the seat. They are also almost 90% efficient in some models, resulting in less heat than A/B amps.

The one drawback of class D amps is the noise. Because of how they function, when the gain is up, there is a noticeable hiss from the speakers. A higher-quality class D will produce less of this signal noise, but it will cost you.

Power

How much power you need is subjective. For the average user who is not relying on massive bass output with sub-woofers, a 50-watt RMS rating will give you volume and clarity. Although bridging channels for a higher power output is possible, it will leave you with fewer speaker options.

However, for more dedicated audiophiles, 50 watts probably won’t do it. If you want to connect an additional sub-woofer, going with 75 watts or more will be safer. This will mitigate the problem of overdriven and distorted speakers and give you plenty of extra power for the bass response and additional tweeters.

It’s a good idea to go for a well-known brand name to ensure quality and prevent overheating issues. A high-quality MOSFET (metal-oxide-semiconductor field-effect transistor) is designed to handle high power levels, giving you high efficiency at low voltage. Choosing an amplifier with a MOSFET installed will help your power efficiency and audio quality.

Conclusion

Overall, the Alpine MRV-F300 is the best 4-channel amp for quality, power output, and affordability. Its class D designation makes it compact and efficient and provides high-quality audio fidelity.

The best four-channel amp for the money is the Boss R1004. It’s an affordable and trustworthy class A/B full-range amplifier with the power and audio quality you’d expect from a class A/B amp without breaking the bank.

There are many features and considerations within the world of four-channel amplifiers, from power to clarity and quality, and it can be somewhat overwhelming. Hopefully, our reviews have helped you navigate the abundance of four-channel options and choose the right amp for your needs.